1. Field of the Invention
This invention relates generally to detection of clogging of the head gaps in a recording apparatus, and more particularly is directed to such detection in an apparatus of the type which, in its record mode, records video or other information signals in successive parallel information tracks on a record tape by means of a plurality of rotary heads repeatedly scanning across the tape and having respective gaps with different azimuth angles for minimizing cross-talk during playback.
2. Description of the Prior Art
Clogging of the gaps of the rotary heads for recording video signals in a video tape recorder (VTR) sometimes occurs and prevents satisfactory recording of the incoming video signals. In a conventional VTR for home use, there is no way to detect clogging of the rotary heads during recording so that the occurrence of clogging can only be detected or determined after the fact, that is, by rewinding the recorded tape and then playing back or reproducing the same and observing the resulting picture on a monitor or television picture tube. Therefore, when a portable video camera and a conventional VTR are used for recording live action or scenes which cannot be conveniently recreated, the undetected occurrence of clogging of the head gaps is very disadvantageous in that the live action or scenes will not be recorded, or at least not recorded with satisfactory resolution and fidelity.
Accordingly, it has been proposed to provide a VTR with an additional rotary head which monitors or reproduces the information signals immediately after the same have been recorded in the skewed information tracks by the rotary recording and reproducing heads, with the result that the output of the additional monitoring head, or the absence of such output, can provide an indication of the occurrence of clogging of the gaps of the main rotary recording heads. However, the provision of an additional rotary head for monitoring the recording of the information or video signals as such recording proceeds entails increased complexity of circuits of the VTR and a consequent increase in the cost thereof.